When Kim (Anne Hathaway) returns to the Buchman family home for the wedding of her sister Rachel (Rosemarie Dewitt), she brings a long history of personal crisis and family conflict along with her. The wedding party’s abundant cast of friends and relations have gathered for an idyllic weekend of feasting, music and love, but Kym—with her black-comic one-liners and knack for bombshell drama—is a catalyst for long-simmering tensions in the family dynamic.